#include "EPollPoller.h"
#include "Logger.h"
#include "Channel.h"

#include <errno.h>
#include <unistd.h>
#include <strings.h>

//channel未添加到poller中
const int kNew = -1; // channel的成员index_=-1
//channel已经添加到poller中
const int kAdded = 1;
const int kDeleted = 2;

EPollPoller::EPollPoller(EventLoop* loop)
    : Poller(loop)
    , epollfd_(::epoll_create1(EPOLL_CLOEXEC))
    , events_(kInitEventListSize) //vector<epoll_event>
{
    if (epollfd_ < 0)
    {
        LOG_FATAL("epoll_create ERROR:%d\n", errno);
    }
}
EPollPoller::~EPollPoller()
{
    ::close(epollfd_);
}

Timestampp EPollPoller::poll(int timeoutMs, ChannelList *activeChannels)
{
    //用LOG_DEBUG输出日志更为合理
    LOG_INFO("func=%s => fd total count:%lu  \n",__FUNCTION__,channels_.size());
    // LOG_DEBUG("func=%s => fd total count:%lu  \n",__FUNCTION__,channels_.size());

    int numEvents = ::epoll_wait(epollfd_, &*events_.begin(), 
                                 static_cast<int>(events_.size()), timeoutMs);
    int saveErrno = errno;
    Timestampp now(Timestampp::now());

    if (numEvents > 0)
    {
        LOG_INFO("%d events happened \n", numEvents);
        // LOG_DEBUG("%d events happened \n", numEvents);

        fillActiveChannels(numEvents, activeChannels);
        if(numEvents == events_.size())
        {
            events_.resize(events_.size() * 2);
        }
    }
    else if (numEvents == 0)
    {
        LOG_DEBUG("%s TIMEOUT! \n",__FUNCTION__);
    }
    else
    {
        if (saveErrno != EINTR)
        {
            errno = saveErrno;
            LOG_ERROR("EPollPoller::poll() err!");
        }
    }
    return now;
}

//channel update remove->Eventloop updateChannel removeChannel->Poller updateChannel
void EPollPoller::updateChannel(Channel *channel)
{
    const int index = channel->index();
    LOG_INFO("func=%s=> fd=%d, events=%d index=%d \n", __FUNCTION__, channel->fd(), channel->events(), index);
    if(index == kNew || index == kDeleted)
    {
        int fd = channel->fd();
        if(index == kNew)
        {
            channels_[fd] = channel;
        }
        channel->set_index(kAdded);
        update(EPOLL_CTL_ADD, channel);
    }
    else //channel已经在poller上注册过
    {
        int fd = channel->fd();
        if(channel->isNoneEvent())
        {
            update(EPOLL_CTL_DEL, channel);
            channel->set_index(kDeleted);
        }
        else
        {
            update(EPOLL_CTL_MOD, channel);
        }
    }
}

//从poller中删除channel
void EPollPoller::removeChannel(Channel *channel)
{
    int fd = channel->fd();
    channels_.erase(fd);

    LOG_INFO("func=%s=> fd=%d\n", __FUNCTION__, fd);
    // LOG_DEBUG("func=%s=> fd=%d\n", __FUNCTION__, fd);

    int index = channel->index();
    if(index == kAdded)
    {
        update(EPOLL_CTL_DEL, channel);
    }
    channel->set_index(kNew);
}

//填写活跃的连接
void EPollPoller::fillActiveChannels(int numEvents, ChannelList *activeChannels) const
{
    for (int i = 0; i < numEvents; ++i)
    {
        Channel *channel = static_cast<Channel*>(events_[i].data.ptr);
        channel->set_revents(events_[i].events);
        activeChannels->push_back(channel);
    }
}

//更新channel通道 epoll_ctl add/mod/del
void EPollPoller::update(int operation, Channel* channel)
{
    epoll_event event;
    bzero(&event, sizeof event);

    int fd = channel->fd();
    event.events = channel->events();
    event.data.fd = fd;
    event.data.ptr = channel;

    if(::epoll_ctl(epollfd_, operation, fd, &event)<0)
    {
        if(operation == EPOLL_CTL_DEL)
        {
            LOG_ERROR("epoll_ctl del error:%d\n", errno);
        }
        else
        {
            LOG_FATAL("epoll_ctl add/mod error:%d\n", errno);
        }
    }
}